Answer:
The final price of the smart phone if you use the store credit card is $339.5
Explanation:
Given;
original price of the smart phone = $679
initial discount = 35%
additional discount if you use the store credit card = 15%
total discount of the smart phone if you use the store credit card
= 35% + 15% = 50%
The final price of the smart phone, if you use the store credit card is given as;
P = 0.5 X $679
P = $339.5
Therefore, the final price of the smart phone if you use the store credit card is $339.5